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The fate of potassium l -tyrosine O - 35 S-sulphate was studied in mice and young rats. The ester was excreted unchanged in the urine of mice but was metabolized in the rat. The inability of the mouse to metabolize potassium l -tyrosine O - 35 S-sulphate is explained by the failure of the ester to penentrate to the appropriate enzyme sites. Autoradiograms obtained following injection of the labelled ester to rats showed that radioisotope accumulated in the renal sub-cortex. The kidney was identified as the site of metabolic conversion in the rat and it was shown that the renal sub-cortex is particularly rich in l -tyrosine O - 35 -S-sulphate-2-oxoglutarate aminotransferase activity. The implications of these findings are discussed in relation to studies on arylsulphate esters in general and in relation to the origin of l -tyrosine O -sulphate residues in fibrinogen.

Various biological and chemical properties of colostrokinin were studied. Vasodilatation in dogs, stimulation of smooth muscles of rats and increasing capillary permeability in guinea pigs were observed as the pharmacological actions. Among these, the change in capillary permeability is the strongest when compared to the activity of bradykinin. Colostrokinin activity is destroyed by chymotrypsin, but only slightly by trypsin. It is more stable in acid than in alkaline solution. This substance is dialyzable, and is soluble in water, in 67% ethanol and in 75% acetone, but not in absolute acetone. The isoelectric point is close to pH 7.4. Phenylalanine and serine were detected as the N -terminal and the C-terminal amino acids respectively. The molecular weight, on the basis of amino acid analysis, was calculated to be about 2000. Colostrokinin absorbs light close to λ = 260 m μ .

It was confirmed that a biologically active substance was released when pretreated bovine colostrum (colostrokininogen) was incubated with human salivary kallikrein. It was also demonstrated that colostrokininogen belongs to the immunolactoglobulin of colostric proteins. Crude colostrokinin was purified by means of adsorption on carboxymethylcellulose, Sephadex gel filtration (G-25, G-10 and G-15) and CM-Sephadex column chromatography. The active fraction obtained after CM-Sephadex column chromatography is homogeneous in thin-layer chromatography (TLC) and paper electrophoresis. The peptide spot and biological activity migrated similarly in paper electrophoresis. The vasodilator activity of 1 mg colostrokinin in dogs corresponds to that of 258 μg bradykinin. The pharmacological activities of colostrokinin qualitatively agreed with those of kinins, such as bradykinin. Vasodilation in dogs, stimulation of smooth muscle of rats, and increase in capillary permeability in guinea pigs were caused by colostrokinin. Finally, it was indicated that colostrokinin might aid in the transport of high molecular weight substances across the neonatal gut of ungulates.

Increased excretion of the glucuronide of 3-hydroxyphenyltrimethyl ammonium in urine occurred in rats pretreated with phenobarbitone after a single intramuscular injection of 14C-neostigmine. No increase in the metabolism of neostigmine to 3-hydroxyphenyltrimethyl ammonium was observed in vitro with microsome preparations from the livers of rats pretreated with phenobarbitone. A significant increase in urinary excretion of the glucuronide of 3-hydroxyphenyltrimethyl ammonium occurred in phenobarbitone pretreated rats after a single injection of 3-hydroxyphenyltrimethyl ammonium.

Carboxymethyl cellulose chromatography permits separation of five distinct toxic proteins from the venom of the Indian cobra ( Naja naja ). These account for 90 per cent of the toxicity against mice. After gel filtration on Sephadex G-50 columns, three of the toxic fractions are more potent than the crude venom by factors of 6–9. They differ from one another in their sensitivities to heat and trypsin inactivation. Phospholipase does not appear to contribute significantly to the lethal effect. The two most abundant fractions, cobramines A and B, are less toxic than the crude venom and account for its cardiotoxic activity.